Analog TDS sensor: specs and pinout
Signal board plus two-needle probe that outputs an analog voltage related to dissolved solids (TDS) in water. Every spec and pin row below is from the original maker's Gravity Analog TDS Sensor (SEN0244) wiki, a reference board: the stocked board is not confirmed to be that board.
Specs
| Spec | Value | Source |
|---|---|---|
| the original maker's SEN0244 reference board: Input voltage | 3.3 V to 5.5 V | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: Output voltage | 0 V to 2.3 V analog | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: Working current | 3 mA to 6 mA | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: TDS measurement range | 0 to 1000 ppm | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: TDS measurement accuracy | +/-10 % F.S. at 25 C | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: Module interface | PH2.0-3P | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: Electrode interface | XH2.54-2P | source Specification section (wiki page for SEN0244) |
| the original maker's SEN0244 reference board: Probe | 2 needles; described as a waterproof probe | source Specification section (wiki page for SEN0244) |
Power
| Value | Source | |
|---|---|---|
| Supply | the original maker's SEN0244 reference board: 3.3 V to 5.5 V (stocked board not confirmed) | source Specification |
| Current | the original maker's SEN0244 reference board: 3 mA to 6 mA (stocked board not confirmed) | source Specification |
Pinout
Pin rows are the labels printed on the original maker's SEN0244 reference board. The stocked board may be a different maker's clone, so check the markings on the board you received.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| - | Power GND | 0 V | source Pin definition | |
| + | Power VCC | 3.3 V to 5.5 V | source Pin definition | |
| A | Analog signal output | 0 V to 2.3 V | source Pin definition | |
| TDS | TDS probe connector | source Pin definition | ||
| LED | Power indicator | source Pin definition |
Build with it
Project ideas for the Analog TDS sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- ESP32 TDS display: On the original maker's reference board the output is 0-2.3 V at a 3.3 V supply; use an ADC attenuation that covers 2.3 V. Learning project, not a drinking-water test.
- TDS with temperature compensation: The probe has no temperature sensor, so a separate waterproof probe supplies the temperature value. Learning project. The DS18B20 data line needs a 4.7 k pull-up to its supply; the resistor pack's values are not listed, so pick the 4.7 k part (yellow, violet, red bands) and confirm it with a multimeter.
- Uno TDS readout: The board accepts 5 V, so it runs directly from the Uno. Learning project.
Common mistakes
- Expecting automatic temperature compensation: the probe has no temperature sensor and the sample code assumes 25 C unless you add one (source)
- Reading it above the stated range: TDS range is 0 to 1000 ppm with +/-10 % F.S. accuracy at 25 C (source)
- Supplying it above 5.5 V: the stated input range is 3.3 V to 5.5 V (source)
Not covered by the official source
- Listing product is not confirmed identical to the original maker's SEN0244; values are that board's published specification.
- Probe cable length is not given reliably and is omitted.
Sources
- link (the original maker's wiki, Gravity: Analog TDS Sensor/Meter, SEN0244; maker page, retrieved 2026-11-07)